scholarly journals Sleep duration and breast cancer incidence: results from the Million Women Study and meta-analysis of published prospective studies

SLEEP ◽  
2020 ◽  
Author(s):  
Angel T Y Wong ◽  
Alicia K Heath ◽  
Tammy Y N Tong ◽  
Gillian K Reeves ◽  
Sarah Floud ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Sleep Duration ◽  
Cancer Incidence ◽  
Prospective Studies ◽  
Average Duration ◽  
Meta Analysis ◽  
Breast Cancer Incidence ◽  
Weighted Average

Abstract Study Objectives To investigate the association between sleep duration and breast cancer incidence, we examined the association in a large UK prospective study and conducted a meta-analysis of prospective studies. Methods In the Million Women Study, usual sleep duration over a 24-h period was collected in 2001 for 713,150 participants without prior cancer, heart problems, stroke, or diabetes (mean age = 60 years). Follow-up for breast cancer was by record linkage to national cancer registry data for 14.3 years on average from the 3-year resurvey. Cox regression models yielded multivariable-adjusted breast cancer relative risks (RR) and 95% confidence intervals (CIs) for sleep duration categories. Published prospective studies of sleep duration and breast cancer risk were included in a meta-analysis, which estimated the inverse-variance weighted average of study-specific log RRs for short and for long versus average duration sleep. Results After excluding the first 5 years to minimize reverse causation bias in the Million Women Study, 24,476 women developed breast cancer. Compared with 7–8 h of sleep, the RRs for <6, 6, 9, and >9 h of sleep were 1.01 (95% CI, 0.95–1.07), 0.99 (0.96–1.03), 1.01 (0.96–1.06), and 1.03 (0.95–1.12), respectively. In a meta-analysis of 14 prospective studies plus the Million Women Study, including 65,410 breast cancer cases, neither short (RR < 7 h = 0.99 [0.98–1.01]) nor long (RR > 8 h = 1.01 [0.98–1.04]) versus average duration sleep was associated with breast cancer risk. Conclusions The totality of the prospective evidence does not support an association between sleep duration and breast cancer risk.

scholarly journals Sleep duration and breast cancer incidence: results from the million women study and a meta-analysis of published prospective studies

2019 ◽  
Vol 64 ◽  
pp. S421-S422
Author(s):  
A.T.Y. Wong ◽  
A.K. Heath ◽  
G.K. Reeves ◽  
S. Floud ◽  
V. Beral ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Sleep Duration ◽  
Cancer Incidence ◽  
Prospective Studies ◽  
Meta Analysis ◽  
Breast Cancer Incidence

Metformin and breast cancer risk: A meta-analysis and critical literature review.

2012 ◽  
Vol 30 (27_suppl) ◽  
pp. 25-25
Author(s):  
Nananda Col ◽  
Leslie Ochs ◽  
Vicky Springmann ◽  
Aaron K Aragaki ◽  
Rowan T. Chlebowski
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Literature Review ◽  
Cancer Incidence ◽  
Invasive Breast Cancer ◽  
Meta Analysis ◽  
Breast Cancer Incidence ◽  
Cochrane Library ◽  
Study Quality

25 Background: Observational studies have suggested that metformin, commonly used for diabetes treatment that increases insulin sensitivity and improves glycemic control, decreases the incidence of several common cancers. However, findings regarding metformin and breast cancer incidence have been mixed. To explore this issue, a systematic literature review and meta-analysis were performed with a focus on potential biases. Methods: We conducted a comprehensive literature search for all pertinent studies addressing metformin use and breast cancer risk by searching Pub Med, Cochrane Library, Scopus (which includes Embase, ISI Web of Science) using the Mesh terms: "metformin" or "biguanides" or "diabetes mellitus, type 2/therapy" and "cancer" or "neoplasms". When multiple hazard ratios (HR) or odds ratio (OR) were reported, the most adjusted estimate was used in the base-case analysis. We pooled the adjusted HR using and performed sensitivity analyses on duration of metformin use (> or < 3 years use), study quality (assessed using the GRADE system), and initial observation year of the cohort (before vs after 1997). Results: From a total of 421 citations, 13 full-text articles were considered, and 7 independent studies were included. All were observational (4 cohort and 3 case control). Our combined OR for metformin association with invasive breast cancer of all 7 studies was 0.83 (95% CI, 0.71-0.97). Funnel plot analyses did not suggest publication bias. Stronger associations were found when analyses were limited to studies estimating the impact of longer metformin duration (OR = 0.75. 95% CI, 0.62-0.91) or among studies that began observing their cohort before 1997 (OR=0.68. 95% CI, 0.55-0.84). Stratification according to study quality did not affect the combined OR but higher quality studies had smaller CI and achieved statistical significance. Interpretation is limited by the observational nature of reports and different comparison groups. Conclusions: Our analyses support a protective effect of metformin on invasive breast cancer incidence among postmenopausal women with diabetes. Clinical trials are needed to determine whether metformin reduces breast cancer risk.

scholarly journals Aromatase and breast cancer susceptibility.

1999 ◽  
pp. 165-173 ◽  
Author(s):  
N M Probst-Hensch ◽  
S A Ingles ◽  
A T Diep ◽  
R W Haile ◽  
F Z Stanczyk ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Cancer Incidence ◽  
Breast Cancer Incidence ◽  
Latina Women ◽  
Repeat Polymorphism ◽  
Cyp19 Gene ◽  
Functional Relevance

Based on experimental and epidemiological evidence it is hypothesized that estrogen increases breast cancer risk by increasing mitotic activity in breast epithelial cells. Aromatase is crucial to the biosynthesis of estrogens and may therefore play a role in breast cancer development. Supporting data for an etiological role of aromatase in breast tumor biology are several-fold. First, the association between weight and postmenopausal breast cancer risk may be mediated by aromatase. Secondly, a pilot study found a higher aromatase expression in normal breast adipose tissue from breast cancer cases as opposed to healthy women. Thirdly, experimental data in animals suggest that aromatase activity predisposes mammary tissue to preneoplastic and neoplastic changes. In a multiethnic cohort study conducted in Los Angeles and on Hawaii we investigated (i) whether the plasma estrone to androstenedione (E1/A) ratio in different ethnic groups was associated with ethnic differences in breast cancer incidence, and (ii) whether genetic variation in the CYP19 gene encoding the P450 aromatase protein was associated with breast cancer risk. The age- and weight-adjusted ethnic specific E1/A ratios x 100 among women without oophorectomy were 7.92 in African-Americans, 8.22 in Japanese, 10.73 in Latinas and 9.29 in non-Latina Whites (P=0.09). The high E1/A ratio in Latina women was not associated with a high breast cancer incidence; in fact Latina women had the lowest breast cancer incidence in the cohort observed so far. We found no consistent association of an intronic (TTTA)n repeat polymorphism with breast cancer risk in different ethnic groups. This polymorphism was not associated with differences in the plasma E1/A ratio in a way that would predict its functional relevance. We describe a newly identified TTC deletion in intron 5 of the CYP19 gene that is associated with the (TTTA)n repeat polymorphism. Neither this polymorphism, nor a polymorphism at codon 264 in exon VII of the CYP19 gene, was associated with breast cancer. We did not identify any genetic variation in exon VIII in 54 African-American subjects. We identified rare genetic variants of unknown functional relevance in the promoter 1.4 of the CYP19 gene in 3 out of 24 Latina women. Further investigation into the role of aromatase in breast cancer etiology is important, given that the potential use of aromatase inhibitors as breast cancer chemopreventives depends on these results.

scholarly journals Consumption of red and processed meat and breast cancer incidence: A systematic review and meta-analysis of prospective studies

2018 ◽  
Vol 143 (11) ◽  
pp. 2787-2799 ◽  
Author(s):  
Maryam S. Farvid ◽  
Mariana C. Stern ◽  
Teresa Norat ◽  
Shizuka Sasazuki ◽  
Paolo Vineis ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Systematic Review ◽  
Cancer Incidence ◽  
Prospective Studies ◽  
Meta Analysis ◽  
Breast Cancer Incidence ◽  
Processed Meat ◽  
Red And Processed Meat

scholarly journals Risk-Reducing Salpingo-Oophorectomy and Breast Cancer Risk Reduction in the Gynecologic Oncology Group Protocol-0199 (GOG-0199)

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Phuong L Mai ◽  
Austin Miller ◽  
Mitchell H Gail ◽  
Steven Skates ◽  
Karen Lu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Cancer Incidence ◽  
Breast Cancer Incidence ◽  
Incidence Rates ◽  
Pathogenic Variant ◽  
Risk Reducing ◽  
Cancer Risk Reduction

Abstract Background Risk-reducing salpingo-oophorectomy (RRSO) has been associated with approximately 50% breast cancer risk reduction among women with a pathogenic variant in BRCA1 or BRCA2 (BRCA1/2), a finding that has recently been questioned. Methods We estimated incidence rates of breast cancer and all cancers combined during 5 years of follow-up among participants selecting RRSO or ovarian cancer screening (OCS) among women with a BRCA1/2 pathogenic variant or strong breast and/or ovarian cancer family history. Ovarian or fallopian tube or peritoneal cancer incidence rates were estimated for the OCS group. Breast cancer hazard ratios (HRs) for time-dependent RRSO were estimated using Cox regression with age time-scale (4943 and 4990 women-years in RRSO and OCS cohorts, respectively). All statistical tests were two-sided. Results The RRSO cohort included 925 participants, and 1453 participants were in the OCS cohort (381 underwent RRSO during follow-up), with 88 incident breast cancers diagnosed. Among BRCA1/2 pathogenic variant carriers, a non-statistically significant lower breast cancer incidence was observed in the RRSO compared with the OCS cohort (HR = 0.86, 95% confidence interval  = 0.45 to 1.67; P = .67). No difference was observed in the overall population or among subgroups stratified by prior breast cancer history or menopausal status. Seven fallopian tube and four ovarian cancers were prospectively diagnosed in the OCS cohort, and one primary peritoneal carcinoma occurred in the RRSO cohort. Conclusions These data suggest that RRSO might be associated with reduced breast cancer incidence among women with a BRCA1/2 pathogenic variant, although the effect, if present, is small. This evolving evidence warrants a thorough discussion regarding the impact of RRSO on breast cancer risk with women considering this intervention.

Serum 25-hydroxyvitamin D and breast cancer risk: a meta-analysis of prospective studies

Tumor Biology ◽  
2013 ◽  
Vol 34 (6) ◽  
pp. 3509-3517 ◽  
Author(s):  
Dan Wang ◽  
Omar Israel Vélez de-la-Paz ◽  
Jun-Xia Zhai ◽  
Dian-Wu Liu
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Risk ◽  
Cancer Risk ◽  
Prospective Studies ◽  
Meta Analysis ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D
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